Abstract:

Objective   To analyze mRNA expressions of matrix metalloproteinases(MMPs) and their inhibitors(TIMPs) in the brain tissue and to investigate the mechanism of leukoaraiosis(LA) caused by blood-brain barrier(BBB) damage. Methods   Five-month-old male spontaneously hypertensive(SH) rats(n=18) were taken as experimental group, the same age male Wistar rats(n=7) were taken as control group. Rat brain tissues were collected for HE staining and immunohistochemical staining to observe pathological changes and expressions of MBP, NF and GFAP. mRNA expressions of MMP-9, MMP-2 and TIMP-1 in the white matter were detected by Real-time PCR. Results   HE staining showed that the number of axons and oligodendrocytes decreased, and astrocytes proliferation in the white matter of SH rats. Comparing to the control group, GFAP expression was increased, while expressions of MBP and NF were decreased in the experimental group. TIMP-1, MMP-9 and MMP-2 mRNA expressions all rised in the white matters of SH rats, among which TIMP-1 and MMP-2 mRNA expressions increased significantly (P<0.05), while MMP-9 mRNA expression didn′t show significant difference(P>0.05). Conclusion   Five-month-old SH rats can be adopted as the animal model of LA, while BBB damage caused by MMPs may be one of pathological mechanisms of LA.

Key words: Leukoaraiosis； Bloodbrain barrier； MMPs； TIMPs； Spontaneously hypertensive rats